Exposure to ambient air pollution and the incidence of lung cancer and breast cancer in the Ontario Population Health and Environment Cohort

Abstract

Lung and female breast cancers are highly prevalent worldwide. Although the association between exposure to ambient fine particulate matter (PM2.5) and lung cancer has been recognized, there is less evidence for associations with other common air pollutants such as nitrogen dioxide (NO2) and ozone (O3). Even less is known about potential associations between these pollutants and breast cancer. We conducted a population‐based cohort study to investigate the associations of chronic exposure to PM2.5, NO2, O3 and redox‐weighted average of NO2 and O3 (Ox) with incident lung and breast cancer, using the Ontario Population Health and Environment Cohort (ONPHEC), which includes all long‐term residents aged 35–85 years who lived in Ontario, Canada, 2001–2015. Incident lung and breast cancers were ascertained using the Ontario Cancer Registry. Annual estimates of exposures were assigned to the residential postal codes of subjects for each year during follow‐up. We used Cox proportional‐hazards models adjusting for personal‐ and neighborhood‐level covariates. Our cohorts for lung and breast cancer analyses included ~4.9 million individuals and ~2.5 million women, respectively. During follow‐up, 100,146 incident cases of lung cancer and 91,146 incident cases of breast cancer were diagnosed. The fully adjusted analyses showed positive associations of lung cancer incidence with PM2.5 (hazard ratio [HR] = 1.02 [95% CI: 1.01–1.05] per 5.3 μg/m3) and NO2 (HR = 1.05 [95% CI: 1.03–1.07] per 14 ppb). No associations with lung cancer were observed for O3 or Ox. Relationships between PM2.5 and NO2 with lung cancer exhibited a sublinear shape. We did not find compelling evidence linking air pollution to breast cancer.

Fine Particulate Matter Exposure and Cancer Incidence: Analysis of SEER Cancer Registry Data from 1992–2016

“…A growing body of evidence indicates that lung cancer incidence is associated with exposure to PM 2:5 (IARC 2013;Bai et al 2020;Zhang et al 2020). The present study supports this evidence, with a statistically significant IRR of 1.19 (95% CI: 1.09, 1.30), even after conservatively adjusting for multiple comparisons (p = 0:01).…”

“…Much of the epidemiological evidence to support this association, however, is based on prospective cohort studies that examined lung cancer mortality, not lung cancer incidence. Although several recent studies have used incidence data to estimate the association between PM 2:5 and lung cancer (IARC 2013;Bai et al 2020;Zhang et al 2020), further research is needed to confirm the association and examine the sensitivity of the results to modeling choices and exposure windows.…”

<p>The Clinical Characteristics and Prognosis of Different Age Patients with Lung Cancer</p>

“…14 Bai et al showed the positive associations of lung cancer incidence with PM2.5 and NO2 in the Ontario Population Health and Environment Cohort. 15 This reminds us that the pathogenesis of young lung cancers and old ones may be different due to changes in external factors.…”

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“…To note that both air pollution and water pollution indices are high (76.91 and 78.08, respectively) [19]. Although, the impact of pollution on the development of breast cancer remains debatable; certain studies affirm a completely negative association linking air pollution to breast cancer [20]. Notably, the psychological and emotional impact of breast cancer diagnosis seen among young patients is stronger and more detrimental when compared to the impact seen in older patients [21].…”